Conveyor Dynamic Analysis Helix Technologies deltaT 6 Copyright

Conveyor Dynamic Analysis Helix Technologies delta-T 6 Copyright, 1991 -2015 © Helix Technologies Pty Ltd

Introduction • Helix Technologies was established in 1991 and Helix software has been exported to more than 25 countries around the world. • Engineering Software - Conveyor Design and Pipe Design software • delta-T 5 Static or Rigid body design software. • Market Research showed need for a Conveyor Dynamic Analysis program.

Research into Dynamic Analysis since 1999 • Various sources such as Bulk Solids Handling by Trans. Tech Publications • Engineering Journals and Doctoral Thesis. • Libraries incl. Delft, Hannover UNI • Mathematical Skills Required. • Consultant - Dr Michael Fisher, Assoc. Professor of Mathematics at UWA.

Mathematical Model • Kelvin solid model

Delta-T 5 Dynamic Analysis module • Uses ‘Static’ Calculation model to capture conveyor geometry, equipment sizes, power ratings etc. • Additional ‘Dynamic data’ input - Belt modulus, Spring Constant, Delay times and Damping factors. • Drive Torque Control vs Speed Control Input • Operating conditions - Starting, Stopping Loading • Boundary Conditions can be changed by user - not hard coded into program

Dynamic Data Input • Simple parameters required • Belt Modulus • Program Calculates Spring Constant, delay time Tau • Enter Calculation Run time in seconds • Choose Starting / Stopping Condition

Dynamic Data Input Form • Belt Modulus • Calculate Delay Time • Select Operating Condition • Press Calculate

Torque Speed Curve • Program allows user to input any profile • Can model DOL, Fluid Coupling, Wound Rotor Motor, VVVF, Variable Speed Drives

Wound Rotor Motor Curve • Example of Wound Rotor Motor profile

Speed Control / Regenerative Conveyors • Aborted Start can be modelled Regenerative Load • Torque Speed curve needs to be extended beyond the 100% Full load Speed % • Tension waves tend to force drive over design speed • Motor acts as brake beyond synchronous speed

Drive Speed vs Time curves • Enter any Time speed relationship

‘S’ Curve Velocity Ramp • S curve • Any function • Paste from Excel • You can add any shape Velocity Ramp for Drive Pulley • Includes ‘S’ curves, Linear ramp, Dwell periods

Multiple Drives / Delay Times • Any Number of Drives can be modelled • Each Drive can have different starting curves • Delay times can be added • Aborted Start can be modelled

Dynamic Calculation • Calculation Run time depends on conveyor • Typically 60, 000 calculation results each for Velocities, Tensions, Strains • 2 seconds up to 20 minutes on Pentium 4/2. 4 GHz PC • Stiff belt (high modulus) lightly loaded is worst case • Variable Step Runge Kutta adjusts calculation to requirements • Progress form indicates progress • Cancel Calculation button

Summary of Dynamic Calculation Procedure • Data Input - simple and easy to use • Drive Torques vs Speed relationships. • Drive Speed vs Time Ramp • Delay Times on Multiple Drives. • Dynamic Calculations. • Graphic Presentation • Print & Export Reports to Word, PDF etc. Run 2 sample calculations

Calculation Examples • Level Conveyor Starting • Level Conveyor Stopping • Inclined Conveyor Stopping • Holdback Tensions • Compare Torque Control Start vs Speed Control Start

Example Level CV 01 • 2600 m long level • 3, 500 tph • ST 1600 x 1, 200 wide belt • 945 k. W installed power • Dual Drives 130% FLT • Brake at Tail

CV 01 Drive Torque • Wound Rotor Motor on all 3 drives

CV 01 Belt Velocities • Final Speed is regulated by Torque Speed Curve • Variable Speed Conveyors can be modelled by reducing speed %

CV 01 Belt Velocity Zoomed in

CV 01 Belt Tensions • Note tension oscillations during starting • Caused by Wound Rotor motor steps

CV 01 Static Calc Tensions • Rigid body calcs shows max T = 374 k. N • Dynamic calcs show max T = 474 k. N

CV 01 Belt Tensions 3 D • Note Tension steps at primary and secondary drives

CV 01 Belt Tensions 3 D • Same graph rotated to different angle

CV 01 Takeup Travel

CV 01 Stopping - Velocities • Stops in about 14 seconds - rigid body calcs = 10. 59 seconds

CV 01 Stopping - Tensions • Note belt slip when slack side tension drops

CV 01 Stopping - Tensions 3 D • Note peak tension after brake

CV 01 Stopping - Tensions 3 D Rotated • Note low tensions before drives

CV 01 Stopping - Tensions 2 D • Low tension point identified from 3 D graph and plotted in 2 D

Inclined Conveyor Starting 3 Drives • 2900 m long 500 m lift • Wound Rotor motors starting 130% FLT • Empty belt absorbed power is only 225 k. W • Conveyor starts very quickly • 3 x 630 k. W drives - starting empty • Large Tension waves force drive over speed - destructive

Inclined Conveyor Starting 1 Drive • 1 x 630 k. W secondary drive - starting empty • Secondary Drive Starts conveyor • Primary Drive has delay time starting empty • Reduced tension waves • Equipment operating within design limits

Inclined Conveyor Tensions 1 Drive starting • Starting Secondary Drive • Reduced tension waves • Still significant waves • Beware High lift conveyors starting empty

Level - Inclined Holdback Example CV 03 • 1000 m long 50 m lift • 710 k. W installed • 2, 500 tph • 1500 mm wide class 2000/5 ply fabric belt • Effect of Holdback on Belt velocities and tensions

CV 03 Stopping Belt Velocities no holdback • Holdback not fitted • Drive Velocity drops quickly • Tail velocity steady and then drops • Both slow to zero in about 7. 5 seconds • Belt starts to run backwards • Indicated by negative velocities

CV 03 Stopping Belt Tensions - no holdback • Holdback not fitted • Drive Tension drops quickly as Torque is removed • Tensions decay and settle at equilibrium

CV 03 Stopping Belt Velocities - with holdback • Holdback fitted • Drive Velocity drops quickly • Tail velocity steady and then drops • Drive drops to zero and is prevented from running backwards • Tail reverses momentarily and then stops

CV 03 Stopping Belt Tensions with holdback • Holdback fitted • Drive Tension drops quickly as Torque is removed • Tensions decay • After drive stops Tension increases as Holdback activates • Required Holdback Tension can be read from graph • Peak and Steady Holdback Tension shown

Declined CV 04 Example • 1590 m long 77 m lower • 250 k. W Tail Drive • 2, 500 tph 3 m/s coal • 1600 mm wide class 1250/4 ply fabric belt • Effect of Holdback on Belt velocities and tensions • Takeup before tail drive • Brake on tail drive

Declined CV 04 Belt Velocities • VSD Start • High Velocity at Head

Declined CV 04 Belt Tensions • VSD Controlled Start • Tension Rise as Drive begins to act as a brake • Red line = into drive • Yellow line = out of drive

Declined CV 04 Belt Tensions 3 D • VSD Controlled Start • Tension Rise as Drive begins to act as a brake

Declined CV 04 Brake Released • Belt Velocities • Brake Released on Fully Loaded Conveyor • Takes 23 seconds for Drive to reach design speed of 3 m/s

Declined CV 04 Stopping • Belt Velocities • Brake at Tail • About 30 seconds to stop (average) • Rigid body calcs = 29. 76 seconds

Declined CV 04 Brake Tensions • Red Line = Into Brake (Slack Side) • Yellow Line = Out of Brake (Tight Side) • Steady state clamping force is shown

Torque Control vs Speed Control • 1000 m long level CV • 250 k. W Drive • 2, 500 tph 5. 2 m/s coal • 1200 mm wide class 500/5 ply fabric belt • 140% FLT Torque Controlled Start 30 seconds to start OR • • Which is best ? 30 second ‘S’ curve velocity ramp

Speed Control Belt Velocities

Speed Control Belt Tensions • 168 k. N max tension

Torque Control Belt Velocities • Velocity fluctuates with tension waves

Torque Control Belt Tensions 2 D • 112 k. N max tension

Speed Control 3 d Tensions • Torque Control is better for this conveyor each CV is different

Dynamic Program Verification • Uses proven delta-T software as basis for capturing data, equipment sizing and basic conveyor design • Dynamic calculations have been verified against Matlab results • Comparison of results against many published papers e. g Muja Conveyor etc. • Results depend on input data, method of calculation employed e. g some published results do not use Torque control, only Speed control because it is easier to program and solve • delta-T uses instantaneous f factor, variable drive torque & has flexible design options so can be matched to any conveyor • Ongoing process of verification with our customers

Operating System Requirements - Delta -T 5 Dynamic Version • Stand alone program - no 3 rd party software required • Requires Windows 32 bit OS i. e Windows 98, 2000, XP • Pentium 4 x 2. 4 GHz with 512 Mb RAM and 1024 x 768 SVGA recommended • Competent Conveyor Design Engineer

Marketing of delta-T 5 Dynamic Program • Program Licences will be sold as a complete package • Includes full rigid body version of delta-T • Training to be integral part of sale • Software support and upgrades are available • Price of software not yet determined - target is to get it down to between $15, 000 to $20, 000

Close • Helix aimed to produce a flexible, powerful design program which can be used by experienced conveyor design engineers Acknowledgements • Dr Michael Fisher • Dave Beckley • Dr Lloyd Townley • All previous publishers of papers Copyright, 1991 -2003 © Helix Technologies Pty Ltd Helix Technologies delta-T 5